This is a picture of the medicine cabinet currently provided by ETI.
The cabinet is made for a bathroom that does not move. When stocked, after a short drive, then the door is opened, the contents will spill all over the bathroom floor.
The interior dimension is 13 1/4” wide.
I ordered tension rods to use as cross pieces to keep the contents in the cabinet and not out.
I’m sure there are more elegant solutions, but this works for us.